QString UnitSystem::displayAmount( double amount, Unit* units, int precision, Unit::unitScale scale )
{
// If the precision is not specified, we take the default one
if( precision < 0)
{
precision = this->precision;
}
// Special cases. Make sure the unit isn't null and that we're
// dealing with volume.
if( units == 0 || units->getUnitType() != _type)
return QString("%L1").arg(amount, fieldWidth, format, precision);
// We really shouldn't ever reference something that could be null until
// after we have verified it isn't.
double SIAmount = units->toSI( amount );
double absSIAmount = qAbs(SIAmount);
Unit* last = 0;
// Don't loop if the 'without' key is defined
if ( scaleToUnit().contains(Unit::scaleWithout) )
scale = Unit::scaleWithout;
// If a specific scale is provided, just use that and don't loop.
if ( scaleToUnit().contains(scale) )
{
Unit* bob = scaleToUnit().value(scale);
return QString("%L1 %2").arg(bob->fromSI(SIAmount), fieldWidth, format, precision).arg(bob->getUnitName());
}
// scaleToUnit() is a QMap which means we loop in the order in which the
// items were inserted. Order counts, and this map has to be
// created from smallest to largest scale (e.g., mg, g, kg).
QMap<Unit::unitScale, Unit*>::const_iterator it;
for( it = scaleToUnit().begin(); it != scaleToUnit().end(); ++it)
{
Unit* bob = it.value();
double boundary = bob->boundary();
// This is a nice bit of work, if I may say so myself. If we've been
// through the loop at least once already, and the boundary condition is
// met, use the Unit* from the last loop.
if ( last && absSIAmount < bob->toSI(boundary) )
return QString("%L1 %2").arg(last->fromSI(SIAmount), fieldWidth, format, precision).arg(last->getUnitName());
// If we get all the way through the map, this will be the largest unit
// available
last = bob;
}
// If we get here, use the largest unit available
if( last )
return QString("%L1 %2").arg(last->fromSI(SIAmount), fieldWidth, format, precision).arg(last->getUnitName());
else
return QString("nounit"); // Should never happen, so be obvious if it does
}
double UnitSystem::amountDisplay( double amount, Unit* units, Unit::unitScale scale )
{
// Special cases. Make sure the unit isn't null and that we're
// dealing with volume.
if( units == 0 || units->getUnitType() != _type)
return amount;
double SIAmount = units->toSI( amount );
double absSIAmount = qAbs(SIAmount);
Unit* last = 0;
// Short circuit if the 'without' key is defined
if ( scaleToUnit().contains(Unit::scaleWithout) )
scale = Unit::scaleWithout;
if ( scaleToUnit().contains(scale) )
{
Unit* bob = scaleToUnit().value(scale);
return bob->fromSI(SIAmount);
}
QMap<Unit::unitScale, Unit*>::const_iterator it;
for( it = scaleToUnit().begin(); it != scaleToUnit().end(); ++it)
{
Unit* bob = it.value();
double boundary = bob->boundary();
if ( last && absSIAmount < bob->toSI(boundary) )
return last->fromSI(SIAmount);
last = bob;
}
// If we get here, use the largest unit available
if( last )
return last->fromSI(SIAmount);
else
return -42.42; // Should never happen, so be obvious if it does
}
